Disconnecting switch



Patented Sept. 13, 1932 UNITED STATESv PATENT OFFICE JOSEPH I). I. HOFFMAN, F KIRKWOOD, MISSOURI, ASSIGNOR TO JAMES R. KEARNEY CORPORATION, OF ST. LOUIS, MISSOURI, A CORPORATION 0F MISSOURI DISCONNECTING SWITCH Application led February 21, 1931.

high tension transmission lines.

The present improvements are applicable particularly to switches of the types characterized by a shell or housing of insulating material which completely encloses the terminals, contacts and live members associated therewith, together with the fuse and fuse cartridge. In such types of switches, the blade or terminal connecting member may be bodily removed from the housing and contact assembly, such construction being particularly applicable Where it is desired to employ a fuse in connection with a removable terminal bridge member. Fuse switch assemblies of the general type noted are usually referred to in the trade as expulsion cutouts.

An. object of this invention is to provide, in a disconnecting switch of the type noted, means for eifectively-frictionally locking the cartridge assembly in position between the contacts within the housing, whereby more than suliicient resistance is offered to unintended outward movement of the cartridge with respect to the housing, the locking means yet being of such a nature as to permit an easy manual Withdrawal of the cartridge and associated contacts, from the housing and fixed contacts.

A further object of the present invention is attained in the provision, for example in an ,expulsion cutout, of a fuse cartridge which is readily detachable from the handle or equivalent manually engageable member, so as to facilitate re-fusing of the cartridge, and further so as to facilitate the renewal of the cartridge in the event such a`step becomes necessary.

Yet another object of the invention is attained in the provision of a detachably connected cartridge and closure for a cartridge housing, whereby the housing may be kept closed even though the cartridge be removed from the housing. A

Yet another object of the present invention consists in the provision of an improved de vice serving the double function of securing a Serial No. 517,453.

fuse cartridgeto the handle portion of an eX- pulsion cutout, and for serving the purpose of frictionally locking the movable switch p0rtions into engagement with the housing o casing of the cutout.

Further objects and advantages of the invention will appear from the following detailed description, considered in connection with the accompanying drawing forming a part of the present disclosure, and in which:

Fig. 1 is a vertical sectional elevation of a cutout assembly embodying the principles of the present invention; Fig. 2 is a side elevation, showing certain features of the cartridge locking arrangement; Fig. 3 is a fragmentary elevation of a portion of the cartridge, the lower portion of the cartridge having been-omitted for clearness; Fig. 4 is a plan View of a modified form of locking ring, and Fig. 5 is a section along line 5-5 of Fig. 3.

Referring now by numerals of reference to the drawing, a tubular shell or housing 5, formed of porcelain or other suitable insulating material, is provided on portions of its external surface with petticoats 6, as is customary on high tension insulator constructions. An internal shoulder 7, disposed at a substantial distance from one end of the housing, and formed as by a decrease of the internal diameter at this point along the housing, serves to seat and position a fixed or stationary contact or terminal ring 8. This member is preferably provided with a foot portion, indicated at 9, adapted to rest against the shoulder 7, and the ring may be held in place by cement 10 or its equivalent, which occupies the space between the ring and housing. Connection with the line is made inside the housing by means of the terminal lug 11, the conductor passing through an aperture (not shown) in the porcelain shell and into an opening 12, where it may be securely held as by a set screw 13. Near 4the opposite end of the housing, but receded an appreciable distance, kis fixedly positioned a second contact ring 14: which may be constructed similarly to and positioned in the manner of, member 8. lA

set screw 15, access to which is obtained from the bottom opening of the housing, serves to secure a line conductor to the lower contact, a conductor passage (not shown) to this member extending through the adjacent wall portion of the housing.

A housing cap or closure 16, preferably of porcelain, excludes moisture from the housing and serves asa handle for the manipulation of the cartridge member, hereinafter described, into and out of the housing.

The cartridge includes a tube 17, which may be formed of fiber or other suitable material and one end of which, by preference, engages a closed metal cap 18, as by threads 19. The explosion chamber indicated at 20 serves to receive one end of a fuse 21, the fuse end being positioned and clamped in this end' of the cartridge as by a threaded plug or set screw 22. Assuming, according to usual practice, that the fuse wire or strip includes a portion of reduced cross sectional area, the preference is to dispose such portion of reduced area within the explosion chamber 20, for obvious reasons. The fuse strip or link being longer than the cartridge, is bent reversely where it emerges from the fiber tube and connection is made at the opposite or lower end thereof with a terminal 23, which is preferably in the nature of a one piece ring. A series of contact clips 24, of longitudinal trend and peripherally disposed about the tube member, are secured adjacent to and extend beyond the terminal member 23. The contact clips 24 preferably conform to the inner surface of the ring 14 and the lower cartridge contact assembly is adapted to be positioned on the tube 17 as by one or more set screws 25.

As thus far described the structure is closely similar to the subject matter of a copending application of Valter A. Heinrich, Serial No. 392,920, filed September 16, 1929, wit-h respect to which the present invention constitutes certain improvements. Referring now particularly to Fig. 3, the chambered cap 18 is by preference provided with an outer annular portion 26, characterized by a peripheral groove 27, near its upper or outer end, and adapted to receive a locking ring 28, best shown in Fig. 4, the purpose of which will hereinafter appear. Near the inner or lower end of the cap is an annular cam portion 29 constituted by a ring-shaped structure of wedge section including a narrow upper beveled surface 30, and, as may be desired, a relatively divergent tapering surface 31. lt is my preference to construct the several portions designated by numerals 26 through 31, except for the locking ring, integrally with the chambered cap 18.

It will appear that the parts 23 and 24 constitute the lower contact assembly on the; cartridge, while the cap 18 and associated structures constitute the upper terminal portion carried by the cartridge, electrical connection being made therebetween by means of the fuse link 21 as above discussed. As a means for effecting electrical connection between the cap 18, and the contact ring 8, I prefer to employ a sleeve 32 extending snugly and frictionally therebetween. This sleeve is preferably formed of resilient material and may be initially of stamped construction and provided with a longitudinal slot 33 extending over the greater portion of its length, this slot terminating upwardly or outwardly in a slotted opening of transverse trend, indicated at 34, the resultant opening in the side wall of the tubular member 32, thus being of substantially T shape. The slot 33 near the point of its connect-ion with slot 34 is preferably of extended width resulting in a shoulder 35 for a purpose hereinafter appearing. The opposite or open end of slot 33 is characterized by a pair of relatively divergently disposed faces 36, serving, as will hereinafter appear, to constrict portions of the locking ring 28, as the cartridge is inserted into member 32. Due to the provision of the longitudinal slot 33, and due also to the inherent resilience of the material, preferably metal, forming the member 32, it will appear that this member is free to spread or expand within limits, as the end of the cartridge is inserted therein.

The wall portions of the member. S2 are preferably characterized by a plureity of evenly peripherally spaced slots 37, shown as being of inverted U shape, four of such slots being provided in the present example, and each resulting in the formation of a resilient tongue member 38, inwardly upset so that their free ends extend toward the intcrior of the sleeve 32, and thus serve to effect a frictional engagement between the sleeve and the annular portion 18 formed on the explosion chamber.

From the above description of parts it is seen that the internal diameter of the sleeve 32 being substantially equal to or normally slightly less than the greatest diameter of portions 18 and 29, the metal cap 18 of the fuse carhidge, upon being inserted into the sleeve, will serve slightly to spread the wall portions of the sleeve member 32 and particularly to force outwardly the friction fingers 38, thus making and maintaining a good electrical contact between the sleeve and the cap or contact 18.

I The ring 28, appearing in Fig. 5, being 'formed of resilient material, may be constricted tol bring its free ends into approximate adjacence, whereby the ring may then be moved upwardly through the slot 33.

, However. when the ring is brought beyond the shoulder 35, the resilience of the ring will force its free ends apart, so that at least one thereof will engage the shoulder 35 and prevent any unintended separation of the cartridge and the sleeve 32. Such removal,

`when desired may, however, be easily effected by manual engagement of the free ends of the ring accompanied by manual withdrawal of the cartridge from the sleeve. It is, of course, understood that the sleeve member 32 may be secured as by cementing, or by any other suitable manner, within the hollow portion of the closure 16.

The modified form of locking ring, shown in Fig. 4, is provided with a safety catch, which prevents an accidental or unintended removal of the ring from cap 18. In operation and purpose, this ring is similar to the ring appearing in Fig. 5, yet may not be removed without first constricting it sufficiently to enable one of the ends to be freed from the hook disposed on the opposite end. This expedient'precludes loss of the ring 28, which might occur during shipment or handling of the cartridge.

The means for locking the fuse cartridge assembly within the housing includes an internal, perpherally beveled portion 39 at the inner end of the sleeve 32. It will appear that the slope of this beveled portion, as well as its location, substantially coincides with the external beveled portion 30 on the member 29 so that, as will appear in Fig. l, these surfaces are normally disposed in adjacence. Obviously, the usual effect of a fuse blown within the cartridge is to impart to the cartridge an upward or outward force which, due to the engagement of surfaces 30 and 39, will tend to spread the walls of the sleeve 32 outwardly, and into locking frictional engagement with the inner surface of the ring 8, this tendency being proportional to the expulsion forces attending the blowing of a fuse. It has been found by experiments and experience that this locking arrangement effectively prevents any movement of the handle or closure relative to the housing under the influence of the usual expulsion forces.

It will appear, however, from the relation of parts as shown in Fig. 1, that when it is desired to withdraw the handle and cartridge from the cutout housing the pulling force is applied through the handle to the sleeve or ring 32, and due to the play and lost-motion provided for between the ring 28 and shoulder 35, the sleeve 32 first tends to separate the beveled surface 39 from the surface 30. Thereafter the sleeve coacts with the locking ring to withdraw the cartridge from the'housing. It will appear that while the beveled portions 30and 39 coact to prevent removal or disturbance of the cartridge by reason of an expulsion lforce applied directly thereto, the arrangement in no wise prevents the easy manual withdrawal of the cartridge for purposes of inspection or re-fusing.

Upon removal from the housing, of the assembly including the cartridge, the sleeve and the handle or cover, the cartridge may easily be removed `from the sleeve by manner surface of the fixed contact 8, nevertheless the handle and fuse cartridge are all freely rotatable within the housing so that upon application or removal, the parts may -be manually rotated for the purpose of wiping or cleaning the contacts.

It will apear that the means for assembling the cartridge to the handle or cutout closure, as well as the provisions for positioning and locking the lcartridge within the housing, embody no expensive or complicated parts, since the sleeve 32 may be formed as by stamping, in a single operation, of sheet metal. That the actuation of the device is in no wise complicated by any additional structure is attested to by the fact that the cartridge assembly may be inserted and withdrawn from the housing by a rectilinear movement and requires no rotation of the handle or other parts to effect locking or unlocking as in the case of certain older types of apparatus.

While the device has been described by making detailed reference to a particular presently preferred embodiment of the invention, it will appear obvious to those skilled in the art that a number of changes may be made in the parts, their combinations and arrangements, without departure from the spirit and full intended scope of the invention as defined by the claims hereto appended.

I claim as my invention:

1. In an expulsion cutout, a housing, a closure for the housing, a fuse cartridge within the housing, means carried by the cartridge and means carried by the closure, said means adapted to coact, responsive to blowing of the fuse, to maintain the closure on the housing. i

tacts, a conducting member disposed between the contact surfaces and, frictionally engaging said contacts, and means, operable upon blowing of the fuse, adapted to increase the frictional relation between said member and one of said contacts.

4. In a switch assembly, a switch member having a contact thereon and movable relative thereto, a stationary Contact, means tending normally to position said contacts relatively, by friction, and means coacting with said movable contact adapted to increase the frictional securenient of said contacts upon application of a force, in one direction, to said movable switch member.

5. In a fuse switch assembly, stationary contacts, a fuse cartridge having contact members thereon adapted to engage the stationary contacts, one of said members being arranged for axial movement relative to the cartridge, and means for increasing the frictional resistance between a pair of said contacts responsive'ly to a force applied endwise of said cartridge.

6. In a fuse switch assembly including fixed contacts. a cartridge having contacts thereon and adapted to bridge the fixed contacts, means on said cartridge normally frictionally positioning said cartridge with respect to said fixed contacts, said means including a conducting member adapted to extend between said fixed, and cartridge contacts, and means coacting with said last named means for resisting relative movement of the cartridge and fixed contacts re sponsively and proportionately to expulsion forces applied to the cartridge.

7. In a fuse switch assembly, an enclosure, stationary contacts carried thereby, a removable fuse cartridge for bridging said contacts, a member for manipulating said cartridge, and means frictionally positioning the parts to permit ready manual removal of the cartridge when the parts are in assembled relation, and means coacting with said first named means, for frictionally resisting movement of the caitridge, proportionately to expulsion forces applied to said cartridge.

8. In a fuse switch assembly, a cartridge, a movable Contact carried by the cartridge, a fixed contact positioned for engagement by the movable contact, a resilient member between portions of said contacts, and means carried by the cartridge for displacing said resilient member toward one of said contacts upon application of a force, in one direction, to said fuse cartridge.

9. In a fuse switch assembly, a fuse car` tridge, a contact carried by the cartridge, a stationary contact arranged for engagement by, and adapted to enclose a portion of said cartridge contact, a resilient member adapted for disposition between portions of said contacts, and means for displacing said resilient member toward the stationary contact upon application of a force, in one direction, to said cartridge.

l0. In a fuse switch assembly, a fuse cartridge, a housing for said cartridge, com

paiiion contacts carried respectively by thel cartridge and the housing, a resilient member adapted substantially to enclose a portion of the cartridge contact and having a portion enclosed by the housing contact, and a wedge member carried by the cartridge and adapted, upon blowing of the fuse, to expand said resilient member into increased frictional engagement with the housing contact.

l1. In a fuse switch assembly, a cartridge, a housing therefor, a contact disposed eX- teinally of the cartridge, a companion contact carried by the housing, a resilient sleeve associated in lost-motion relation with the cartridge, and adapted normally to extend between said contacts, and a wedge ring carried by the cartridge and adapted upon application of force thereto, to displace said sleeve outwardly into increased frictional engage ment with the housing contact.

l2. In a switch assembly, a blade member, a handle member, a slotted portion on one of said members, an expansible element carried by the other member and adapted upon application to the slotted member, to extend into a slot therein for securing the members in assembled relation.

13. In a switch assembly, a blade member, a handle, a slotted receptacle associated with the handle, an expansible element carried by the blade member and adapted for insertion in said receptacle, and upon being substantially seated therein adapted to extend into the slotted portion thereof.

14. In an enclosed fuse switch assembly, a cartridge, a contact carried bythe carltridge, a fixed contact carried by the enclosure and positioned for engagement by the first named contact, a radially movable member disposed between portions of said contacts, and an element cariied by the cartridge and provided with a cam surface adapted for displacing engagement with said radially movable member, and adapted to bring such member into frictional engagement with said fixed contact.

l5. In an enclosed fuse switch assembly, a fuse cartridge, contacts carried by the cartridge, fixed contacts positioned in the enclosure for engagement bythe cartridge contacts, a member adapted to extend between one of said fixed and one of said cartridge contacts and having a beveled surface formed thereon, means forming a companion beveled surface on the cartridge member and means associating said cartridge member and said first named member for a limited relative movement endwise of the cartridge member and in a direction to separate said beveled surfaces.

16. In a switch assembly, a blade member, a handle adapted for actuating the blade member, and means detachably associating the blade member and handle, said means including a sleeve carried by the handle and having a slot therein, a resilient locking meinber carried near one end of the blade meniber, adapted to be inserted in said sleeve, the slot in said sleeve being shaped to permit the ready introduction of said blade and locking members and adapted, upon seating the blade member therein, to coact with sai expansible member to secure the blade mem- 5 ber and sleeve in detachably assembled relation.

17. In a fuse switch assembly, a fuse cartridge, a handle for manipulating the cartridge, a resilient, substantially annular member carried by the handle and provided with a slot, a resilient locking ring carried externally of, and near one end of the cartridge, such end of the cartridge being adapted for insertion, with said locking member,

in said annular member; said slot being shaped to permit the ready introduction of the cartridge and resilient member and upon assembly thereof, to lock the cartridge and handle in detachably assembled relation.

18. In a fuse switch assembly, a fuse cartridge, a. handle for manipulating the cartridge, a resilient tubular extension disposed inwardly of the handle and adapted to receive one end of the cartridge, said extension being provided with a slot; means forming companion seats on the cartridge and tubular member respectively, a locking member carried by the cartridge, and a seat for the locking member, associated with said tubular portion.

19. In a fuse switch assembly, a housing, a cartridge, a handle for the cartridge forming a closure for said housing, a resilient sleeve carried by the handle and extending into the housing, said sleeve being provided with a slot and having a beveled inner edge portion, an expansible locking ring carried y the cartridge, means forming a seating recess for said locking ring, near one end of the cartridge, a ring of wedge section carried by the cartridge, and normally adapted closely to engage and coincide with the beveled edge portion of said sleeve, said locking ring adapted to extend into the slot in said sleeve,

and upon expansion in said slot to secure the cartridge and handle in detachably assembled relation.

JOSEPH D. P. HOFFMAN. 

